The Open University has its headquarters in Milton Keynes, north of London in the UK.
However, it is possible to study just about all of the undergraduate courses on offer (about 200 at last count) by Supported Distance Learning, which means you get a tutor to chase you for your assignments.
A blend of materials is used to teach each course, and the specific mix depends on what suited the subject best. These materials are sent to you by post, or are available over the internet, or a combination of both. You just sign up for one course at a time: this could be a short (12 week) course giving you 10 credit points in something like "Writing poetry" or "Exploring Mars" (pity about Beagle!), or an 8-month 60-point course in "Crime, order and social control". There are also a number of courses being offered with an emphasis on e-learning, where tuition is done through the internet. With the right motivation you can accumulate 360 points at the appropriate levels and apply for a Bachelor degree.
Students in Germany
You do not need an "Abitur" or similar to apply for undergraduate courses, however you need to be over 18. I would assume that if you are reading this you are resident in Germany and good at English, two other entry criteria.
The only downside is that the courses are not cheap. However, you can arrange to pay by instalments to spread the burden.
There are about 1200 students in the whole of Germany with the postgraduate MBA programme being the most popular.
Contact
There is comprehensive information on the web at http://www.open.ac.uk
...and you can contact the local representative, Matthew Hawkes on m.hawkes@open.ac.uk